The present invention relates, in general, to a method and apparatus for installing borehole heat exchangers in the earth.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
In the geothermic field, in particular when exploiting the geothermal energy for heating homes is involved, borehole heat exchangers are introduced into the earth through excavation of the ground or through drilling channels. Insofar as the heat exchangers are not installed open, it is common to drill vertical channels, for example with an augering device and to then install the borehole heat exchangers into the borehole.
U.S. Pat. No. 5,634,515 describes a method and a respective apparatus for installing heat exchangers into a borehole. This apparatus is intended to enable a simplified installation of geothermal systems in the earth, useful in particular for already existing building structures. The heat exchangers are hereby installed trenchless, however not vertical but horizontal. A drilling device bores several channels into the earth. In a second step, the respective heat exchangers are pushed into these boreholes.
A problem common to known trenchless methods is the absence of an optimum contact between earth and heat exchanger so that heat conduction is impaired and the heat exchangers are sometimes not secured enough.
It would therefore be desirable and advantageous to address this problem and to obviate other prior art shortcomings